986
AWUS01 KWNH 102051
FFGMPD
WIZ000-ILZ000-IAZ000-110159-

Mesoscale Precipitation Discussion 0897
NWS Weather Prediction Center College Park MD
450 PM EDT Sun Aug 10 2025

Areas affected...portions of northeast IA & southwest WI

Concerning...Heavy rainfall...Flash flooding possible

Valid 102049Z - 110159Z

Summary...A small cluster of thunderstorms is trying to organize
as it moves east-northeast.  Hourly amounts to 2" with local
totals to 4" are possible, which could lead to isolated to widely
scattered instances of flash flooding.

Discussion...A small convective cluster is trying to grow in
coverage and intensity as it moves east-northeast near a frontal
wave within a zone of 850 hPa wind confluence.  Precipitable water
values are ~1.8".  ML CAPE in its vicinity is 500-2000 J/kg and
CIN has been eroding from west-southwest to east-northeast.
Effective bulk shear of ~30 kts exists near this cluster.

The main concern would be that the cluster grows much further in
size and organization, as it is tracking into an area that
received 2-5" of rainfall during the past 24 hours.  Hourly
rainfall up to 2" with local amounts to 4" appear possible, given
the ingredients available.  Recent HRRR runs have had some concept
of future expectations in respect to locations impacted, and shows
the cluster evolving into a forward propagating line by 02z as
instability begins to decline, which would lessen the heavy rain
threat from that point forward.

Roth

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...ARX...DMX...DVN...MKX...

ATTN...RFC...MSR...NWC...

LAT...LON   43469082 43338986 42668996 42359046 42059228
            42019248 42039296 42619254 43029200 43309145